Along with the popularization of the internet and intranet, there has recently been paid attention to an information distribution system for live broadcasting the status of a lecture or a concert in a similar manner to that of a prior-art television broadcasting. According to this system, stream information that a client can reproduce in real time is generated from image data and voice data based on a streaming technique, and this stream information is distributed to a plurality of clients at the same time through a network. Providers of such an information distribution service are not only carrying out a simple distribution of the stream information but also are groping for a provision of higher value-added services in line with the growing trend of multimedia.
Conventionally, under the environments of internet and intranet, there has so far been diffused an information distribution system for real-time distributing the status of a lecture, a concert or the like as stream information (moving picture data and voice data) to the service receivers. This information distribution system is structured by a video camera and a microphone installed respectively at the place of a lecture or a concert, and a stream server for generating stream information (contents information) that can be reproduced by moving picture data and voice data from the video camera and microphone in real time by using a streaming technique and for distributing this stream information to a plurality of clients through an internet or the like.
Each of the plurality of clients receives the stream information and reproduces this stream information in real time. Recently, this information distribution system has come to attract considerable attention as the system can distribute stream information so long as there are clients connected to the internet or the like.
As explained above, in the prior-art information distribution system, the client can reproduce a plurality of kinds of stream information at the same time. However, there is no external control applied to this reproduction. Therefore, this system has a drawback in that when more than necessary stream information has been reproduced in real time, the contents information that is most necessary is easily missed. In the worst case, there is considered a situation where the volume of stream information received is beyond the processing capacity at the client side so that it is not possible to reproduce any information.
Further, there is no external control applied to the stream server side either. Therefore, the stream server can distribute as much volume of a plurality of stream information as possible. In this case, there is considered a case where the traffic volume of the internet and others exceeds a prescribed value and a congestion occurs so that the channel utilization efficiency is lowered extremely.
Further, the prior-art information distribution system is a broadcasting type system which is specialized in the distribution of stream information that can be reproduced in real time. Therefore, this system makes no difference from the existing television broadcasting system in that the contents information is reproduced in real time.
Thus, when the prior-art information distribution system is compared with the existing television broadcasting system in the aspect of cost, the information distribution system requires a higher connection charge to be paid to the telecommunications service enterprises for the utilization of a network. On the other hand, the television broadcasting system requires a substantially lower cost of connection charge. Accordingly, when only the cost aspect is compared, it can be said that the prior-art information distribution system cannot compete at all with the existing television broadcasting system.
Under the above circumstances, providers of the information distribution service using the information distribution system have not limited their services to a simple distribution of the stream information but have been groping for a provision of higher value-added services. However, at present, the providers have not yet found decisive services that can compete with the services of the existing television broadcasting system.